Iron- And Copper-Containing Zeolite Beta From Organotemplate-Free Synthesis And Use Thereof In The Selective Catalytic Reduction Of NOx

Abstract

Provided is a process for the production of a zeolitic material having a BEA-type framework structure comprising YO 2 and X 2 O 3 . The process comprises the steps of (1) preparing a mixture comprising one or more sources for YO 2 , one or more sources for X 2 O 3 , and seed crystals comprising one or more zeolitic materials having a BEA-type framework structure; (2) crystallizing the mixture; and (3) subjecting the zeolitic material having a BEA-type framework structure to an ion-exchange procedure with Cu and/or Fe. Y is a tetravalent element, and X is a trivalent element. The mixture does not contain an organotemplate as structure-directing agent, and the total amount of Cu and/or Fe in the ion-exchanged material ranges from 0.1 to 25 wt.-% calculated as Fe 2 O 3 and CuO. Also provided is a zeolitic material having a BEA-type framework structure, and a method for the treatment of NO x by selective catalytic reduction (SCR).

What is claimed is: 
     
         1 . A process for the production of a zeolitic material having a BEA-type framework structure comprising YO 2  and X 2 O 3 , wherein the process comprises the steps of
 (1) preparing a mixture comprising one or more sources for YO 2 , one or more sources for X 2 O 3 , and seed crystals comprising one or more zeolitic materials having a BEA-type framework structure;   (2) crystallizing the mixture obtained in step (1); and   (3) subjecting the zeolitic material having a BEA-type framework structure obtained in step (2) to an ion-exchange procedure with Cu and/or Fe; wherein Y is a tetravalent element, and X is a trivalent element, wherein the mixture provided in step (1) and crystallized in step (2) does not contain an organotemplate as structure-directing agent, and   
       wherein the total amount of Cu and/or Fe in the ion-exchanged material obtained in step (3) ranges from 0.1 to 25 wt.-% calculated as Fe 2 O 3  and CuO. 
     
     
         2 . The process of  claim 1 , wherein the zeolitic material obtained in step (2) comprises one or more alkali metals M, wherein M is selected from the group consisting of Li, Na, K, Cs, and combinations of two or more thereof. 
     
     
         3 . The process of  claim 1 , wherein Y is selected from the group consisting of Si, Sn, Ti, Zr, Ge, and a mixture of two or more thereof. 
     
     
         4 . The process of  claim 1 , wherein the one or more sources for YO 2  provided in step (1) comprises one or more silicates. 
     
     
         5 . The process of  claim 4 , wherein the one or more sources for YO 2  further comprises one or more silicas in addition to the one or more silicates. 
     
     
         6 . The process of  claim 4 , wherein the mixture provided in step (1) comprises water glass. 
     
     
         7 . The process of  claim 1 , wherein X is selected from the group consisting of Al, B, In, Ga, and a mixture of two or more thereof. 
     
     
         8 . The process of  claim 1 , wherein the one or more sources for X 2 O 3  comprises one or more aluminate salts. 
     
     
         9 . The process of  claim 1 , wherein the molar ratio YO 2 :X 2 O 3  of the mixture according to step (1) ranges from 1 to 200. 
     
     
         10 . The process of  claim 1 , wherein the amount of seed crystals comprised in the mixture according to step (1) ranges from 0.1 to 30 wt.-% based on 100 wt.-% of YO 2  in the one or more sources for YO 2 . 
     
     
         11 . The process of  claim 1 , wherein the mixture according to step (1) further comprises one or more solvents. 
     
     
         12 . The process of  claim 11 , wherein the molar ratio H 2 O:YO 2  of the mixture according to step (1) ranges from 5 to 100. 
     
     
         13 . The process of  claim 1 , wherein the molar ratio M:YO 2  in the mixture according to step (1) ranges from 0.05 to 5. 
     
     
         14 . The process of  claim 1 , wherein the molar ratio YO 2 :X 2 O 3 :M molar ratio in the mixture according to step (1) range from (1 to 200): 1: (0.5 to 100). 
     
     
         15 . The process of  claim 1 , wherein the crystallization in step (2) involves heating of the mixture at a temperature ranging from 80 to 200° C. 
     
     
         16 . The process of  claim 15 , wherein the crystallization in step (2) is conducted under solvothermal conditions. 
     
     
         17 . The process of  claim 15 , wherein the crystallization in step (2) involves heating of the mixture for a period ranging from 5 to 200 h. 
     
     
         18 . The process of  claim 1 , wherein after step (2) and prior to step (3) the process further comprises one or more of the following steps of:
 (i) isolating the zeolitic material having a BEA-type framework structure obtained in step (2), and   (ii) optionally washing the zeolitic material having a BEA-type framework structure obtained in step (2); and/or   (iii) optionally drying the zeolitic material having a BEA-type framework structure obtained in step (2);   wherein the steps (i) and/or (ii) and/or (iii) can be conducted in any order, and wherein one or more of the steps is repeated one or more times.   
     
     
         19 . The process of  claim 1 , wherein the ion-exchange of the zeolitic material having a BEA-type framework structure in step (3) comprises one or more of the steps of:
 (3a) optionally exchanging one or more of the ionic non-framework elements contained in the zeolitic material having a BEA-type framework structure obtained in step (2) against H +  and/or NH 4   + ; and/or   (3b) optionally calcining the zeolitic material having a BEA-type framework structure obtained in step (2) or (3a); and/or   (3c) exchanging one or more of the ionic non-framework elements contained in the zeolitic material having a BEA-type framework structure obtained in any of steps (2), (3a), or (3b) against Cu and/or Fe.   
     
     
         20 . The process of  claim 1 , wherein the zeolitic material having a BEA-type framework structure formed in step (2) comprises zeolite beta. 
     
     
         21 . The process of  claim 1 , wherein the seed crystals comprise a zeolitic material having a BEA-type framework structure. 
     
     
         22 . A zeolitic material having a BEA-type framework structure obtained according to the process of  claim 1 . 
     
     
         23 . A zeolitic material having a BEA-type framework structure, optionally obtained according to the process of  claim 1 , having an X-ray diffraction pattern comprising at least the following reflections: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Intensity (%) 
                   Diffraction angle 2θ/° [Cu K(alpha 1)] 
                 
                     
                     
                 
                     
                   [11-31] 
                   [21.07-21.27] 
                 
                     
                   100 
                   [22.12-22.32] 
                 
                     
                   [13-33] 
                   [25.01-25.21] 
                 
                     
                   [17-37] 
                   [25.53-25.73] 
                 
                     
                   [13-33] 
                   [26.78-26.98] 
                 
                     
                   [11-31] 
                   [28.39-28.59] 
                 
                     
                   [22-42] 
                   [29.24-29.44] 
                 
                     
                    [6-26] 
                   [30.00-30.20] 
                 
                     
                    [9-29] 
                   [32.86-33.26] 
                 
                     
                   [11-31] 
                   [42.90-43.30] 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
         wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern, 
         wherein the BEA-type framework structure comprises YO 2  and X 2 O 3 , wherein Y is a tetravalent element, and X is a trivalent element, and wherein the zeolitic material comprises Cu and/or Fe as non-framework elements in a loading ranging from 0.1 to 25 wt.-% calculated as Fe 2 O 3  and CuO. 
       
     
     
         24 . The zeolitic material of  claim 22 , wherein the YO 2 :X 2 O 3  molar ratio ranges from 2 to 100. 
     
     
         25 . The zeolitic material of  claim 22 , wherein the molar ratio of Cu:X 2 O 3  ranges from 0.005 to 2. 
     
     
         26 . The zeolitic material of  claim 22 , wherein the molar ratio of Fe:X 2 O 3  ranges from 0.005 to 2. 
     
     
         27 . The zeolitic material of  claim 22 , wherein Y is selected from the group consisting of Si, Sn, Ti, Zr, Ge, and a mixture of two or more thereof. 
     
     
         28 . The zeolitic material of  claim 22 , wherein X is selected from the group consisting of Al, B, In, Ga, and a mixture of two or more thereof. 
     
     
         29 . A method for the treatment of NO x  by selective catalytic reduction (SCR) comprising:
 (a) providing a catalyst comprising the zeolitic material of  claim 22 ; and   (b) contacting a gas stream comprising NO x  with the catalyst provided in step (a).   
     
     
         30 . The method of  claim 29 , wherein the gas stream further comprises one or more reducing agents. 
     
     
         31 . The method of  claim 29 , wherein the gas stream comprises one or more NO x  containing waste gases. 
     
     
         32 . The method of  claim 29 , wherein the gas stream comprises a NO x  containing waste gas stream from an internal combustion engine. 
     
     
         33 . A method using the zeolitic material of  claim 22  in a catalytic process, the method comprising using the zeolitic material as a catalyst.